1. Field of the Invention
The present invention relates to devices such as smart phones which generate audio signals, and more specifically to a headset detector in such a device.
2. Related Art
Devices such as radios, mobile phones, MP3-players, tape recorders often generate audio signals (e.g., music or voice). In a typical scenario, an analog signal (or digital data) representing the audio signal is received either from a local medium (e.g., audio tape, laser disk) or from an external source (e.g., network, air), and audio signals are generated for the users.
Headsets are often used associated with such devices. A headset generally refers to an apparatus which has one or more earphones that can be placed in the proximity of the ears of a user, and the audio signals generated by the device can be heard by the user by inserting a pre-specified end into the device. The audible signals are received through the headset and heard by the user having an earphone close to the ear.
A device may contain a headset detector to provide various features. For example, a prior embodiment may contain a mechanical switch which moves into a specific position when a headset is inserted into the device, and a headset detector detects the presence of the headset based on the position of the mechanical switch. The device may operate differently (e.g., play audio signals only through the headset if the headset is present) depending on whether the headset is detected to be present or absent.
One problem with such a mechanical switch based solution is that mechanical implementations are generally susceptible to failure and the complexity of integrating the corresponding solutions into electrical/electronic devices is high. In addition, the mechanical implementations are generally space consuming. At least for some of such reasons, it is generally desirable to provide an improved approach by which the presence (upon insertion) of a headset can be detected.
In addition, it may be desirable for the headset detector to detect the type of headset inserted into the device. As is well known, headsets are of multiple types, each generally suited for specific devices and environments. For example, a stereo headset contains two speakers and no microphone, can be used to play music, and is suited for use associated with MP3 player type of devices. On the other hand, a cellular headset used associated with mobile phones contains a speaker and a microphone, and enables a user to place/answer a call. As another example, a stereo+cellular headset contains two speakers and a microphone, and can be used as a combination of stereo and cellular headsets.
Once the headset type is detected, a device may interface as suited for the specific headset. Such a feature may be particularly useful in devices such as smart phones which may operate as cell phone, MP3 player, radio, etc., and a single/common jack may be provided to insert any of the headset types. Based on the type of headset detected to be present in the jack, a device can operate to perform only the specific features supported by the headset. Advantages such as using all the available resources (e.g., electrical power, processing power) only for the relevant features may be attained as a result.